This invention relates to a label of the type generally referred to as an in-mold label, which is molded into the surface of a blow-molded plastic container at the time the container is manufactured. More particularly, it relates to a two-ply label of the foregoing type in which the top ply can be easily removed from the container by a consumer, leaving the bottom ply attached to the container, with no tacky adhesive residue on either the removed top ply or on the remaining base ply.
It is known in the coupon and label art to provide a two-ply label in which a top ply is easily removable, leaving a base label attached to a substrate and no tacky residue on either ply. The top ply can be a coupon or other promotional device, and the base ply can be a printed label or can be a clear material. This type of label is described in U.S. Pat. No. 4,479,838, which is commonly assigned, and the teachings of which are incorporated herein by reference. This type of two-ply label has not previously been adapted to use on a blow-molded container where the label is molded into the surface of the container.
Previous attempts to adapt this type of two-ply label to a blow-molded container have met with problems such as those caused by the contraction of the plastic when it comes out of the mold and cools. The label, being made from a different material than the plastic of the container, does not shrink at the same rate as the container. The two plies of the label must therefore be sufficiently adaptable to this contraction to remain firmly enough in contact with each other to provide a smooth surface once the bottle has come to room temperature. At the same time, the bond between the two plies of the label must be weak enough to enable the consumer to readily remove the top ply from the bottom ply.
This invention overcomes these difficulties to provide a two-ply type label which can be molded into a blow-molded container, using standard blow molding and in-mold labelling equipment, while affording a smooth label surface on the container.
It is an advantage of the invention to provide a two-ply type label which can be molded to a blow molded container.
It is another advantage of the invention to provide a two-ply type label of the foregoing type which affords a substantially smooth label surface on the blow molded container.
It is yet another advantage of the invention to provide a two-ply type label of the foregoing type which can be molded to a blow molded container without modification to a standard blow molding machine.
It is still another advantage of the invention to provide a two-ply type label of the foregoing type which affords easy removal of the top ply from the base label.
It is another advantage of the invention to provide a two-ply type label of the foregoing type without major modifications to standard label materials.